checkai.
API available

Create your server key and purchase prepaid credits in the developer console. Processing is subject to available capacity.

Check AI for developers

Your application.
Our writing tools.

Bring AI detection and humanization into your own workflow. A prepaid API, with clear word-based usage and no required monthly subscription.

Explore the documentationAsk about API access
Your appServer-side request
DetectReview AI writing signals1 credit / input word
HumanizeRework a passage4 credits / input word
Check AI APIJSON responses

Top up when you need to.

One-time recharges in USD; applicable taxes are added at checkout. A separate API balance, independent of workspace plans.

Prepaid credits · no automatic renewal

Launch

$10one-time recharge

40,000 API credits

Detection only
40,000 words
Humanization only
10,000 words

Or mix both tools using the same credit balance.

Buy Launch

Build

$25one-time recharge

125,000 API credits

Detection only
125,000 words
Humanization only
31,250 words

Or mix both tools using the same credit balance.

Buy Build

Grow

$50one-time recharge

300,000 API credits

Detection only
300,000 words
Humanization only
75,000 words

Or mix both tools using the same credit balance.

Buy Grow

The word amounts above are alternatives, not combined allowances. Unused API credits have no scheduled expiry. Purchase and refund conditions are available in our terms; the final price and taxes are confirmed at checkout. No automatic recharge is enabled.

Plan a request, down to the word.

Estimate your usage before integrating. No text is submitted and no credits are spent.

5,000estimated credits

Detecting and humanizing the same 1,000 words uses 5,000 credits. Each new processing operation uses credits.

Your own API key

Server-to-server access with a Check AI key. Create and revoke keys in your developer console when access is enabled.

Usage you can calculate

One rate for detection, one for humanization. Check the credit estimate before processing.

A contract to review

Review authentication, endpoints and error handling before you build.

Read the API documentation

Before you integrate

Can I buy API credits or generate a key today?

Yes. Sign in with a verified account, open the developer console, create a key and buy a credit pack. Keep your key private on your server.

Does my workspace subscription include this API?

No. The developer balance is separate from workspace subscriptions, monthly allowances and existing workspace credit packs.

What happens if I detect a humanized text?

Both operations count. Humanizing 1,000 input words uses 4,000 credits. Detecting 1,000 words uses another 1,000 credits. The actual word count sent to each tool determines its estimate.

Will plagiarism checking be included?

Version 1 covers AI detection and humanization. Plagiarism, paraphrasing and summarization are outside this API offering.

Can an AI score prove who wrote a text?

No. Detection provides a probabilistic signal with possible false positives and false negatives. Humanization does not guarantee a particular detector score. Always review the text and its context.